Hydraulic control for drilling apparatus



Sept. 12, 1950 R. R. HAYS HYDRAULIC CONTROL FOR DRILLING APPARATUS FiledEfqb. 26, 1946 A i. 4 J

Patented Sept. 12, 1950 orsiiii'li liUUitl HYDRAULIC CONTROL FORDRILLING APPARATUS Russell R. Hays, Lawrence, Kans.

Application February 26, 1946, Serial No. 650,276

6 Claims.

This invention relates to the drilling of lateral drainage channelstransversely to a well bore, and more particularly to a method andapparatus for feeding a fluid supply hose that carries a hydraulicallyoperated drill on its extending end into a hose turner such as thatdescribed in copending application Serial No. 687,028, now abandoned.

The apparatus used is broadly that described in Patent No. 2,345,816, inwhich a hose turning case containing a curved passageway for turning ahigh pressure hose through a 90 arc is run into a well bore on a stringof tubing and positioned opposite a fluid bearing formation bymeans ofan anchor carried on the bottom of the case. The well bore is filledwith water and a high pressure hose carrying either a hydraulicallyoperated water drill or a cutting nozzle at its end is run down thetubing, through the hose turner, and extended out against the formationfor cutting lateral drainage channels therein, the cuttings beingcarried by the fluid exhausted from the drill, back into the well bore,and hence to the surface.

In horizontal drilling apparatus of this general type, variousadaptations of the hydraulic control used to regulate drilling pressureswith a conventional rotary drill have been proposed. These adaptationsare of two types. In the first, a hydraulic cylinder on the drillingplatform is used to relatively raise or lower a fluid supply conduit orother power transmission means operative to power a lateral drillingmechanism positioned at the bottom of a well bore. The up and downmotion transmitted by the cylinder to the conduit is converted throughsuitable transmission means to backward and forward movement of a drillor high pressure cutting nozzle being projected transversely from thewell bore. In the second type of adaptation, the equivalent of ahydraulic cylinder at the bottom of the hole is operated by fluidpressure to project a conduit transversely with a more or less uniformfeeding pressure.

Either method is in itself inadequate primarily because the hydraulicchamber pressures do not accurately define the drilling pressureactually attained. The forces chiefly responsible for this inaccuracyare inertia and friction. Inertia forces become extreme in the case ofmovement of a conduit substantially the length of the well bore. Inwells of any depth the weight of this conduit will be relatively greatwhereas any equipment capable of being turned in the bottom of a wellbore through a 90 arc of small radius must of necessity be of relativelylight and fragile construction. The process of turning the conduitinvolves considerable friction as does its projection in a lateralagainst a return flow necessary for flushing cuttings from the lateralbore. These friction forces may or may not vary, but the hardness of theformation is almost certain to vary through a considerable range. Thedirect consequence of this is that with slowing of the drill, thedownward moving supply conduit may by its inertia transmit within afraction of a second a load in excess of its weight to the drill andconduit turning mechanism.

Where the destructive nature of this type of lateral feed has beenrecognized, attention has centered on the prevention of overloads byhydraulically feeding the conduit from the bottom of the hole. In thismethod the equivalent of a piston carrying the lateral conduit on itslower end is hydraulically forced from a cylinder by fluid carried in afixed string of tubing. Here the force applied to the piston isrelatively constant whereas the required feeding pressure may varywidely in response to varying hardness of the formation, varyingfriction loads and varying inertia loads. In brief, although danger ofoverloads is circumvented by this method, the operator at the surfacehas no way of knowing whether a lateral is actually being out, muchless' means of accurately controlling his feeding pressure.

When it is considered that any small bore drilling mechanism,particularly when it is of relatively light construction, is highlysensitive to feeding pressures, it becomes evident that the problem ofcorrectly feeding a lateral drilling device is a highly specialized one.With an operator at the surface controlling the pressure applied to adrill head within an optimum range of a few pounds when the drill isoperating horizontally at a distance of half a mile or more, certainbasic requirements may be set up.

These are:

1. Accurate and instantaneous knowledge of the pressure being applied.

2. Finger-tip or even electronic control of this feeding pressure fromthe surface.

3. Prevention of inertia overloads to the horizontally operatingequipment at the bottom of the hole.

4. Provision for simply and quickly removing the drilling parts from thehole for repairs and the changing of drills.

When a fluid motor is used as the drill activating means for a lateraldrill, the operation of this motor propagates shock waves in the fiuidsupply stream having a frequency substantially that of the motor. Thisis especially true of motors having a reciprocating action such as thatdescribed in co-pending application Serial No. 604,964. now Patent No.2,441,881. This frequency may be picked up by a vibrating reed frequencymeter mounted on the fluid supply line at a point adjacent its entryinto the well bore. With a turbine type motor excessive feeding pressureacts to decrease the motors R. P. M. With the reciprocating type motornow used, excessive feeding pressure acts to progressively increase thefrequency to slightly in excess of its minimum frequency for a givenpressure before the motor kills. In either case, the frequency range fora given line pressure having been determined, the operator has at hisdisposal instantaneous and accurate means for observing the feedingpressure being applied.

. Finger-tip control of the drill head necessarily precludes the dangerof inertia overloads by the nature of its attainment. To being with, theapparatus is broken down into two types of design. That run into thewell bore and carrying a hose turner positioned opposite the formationto be drilled, follows conventional oil field practice in being ofrugged construction and capable of being run with ordinary tools. Thisis referred to as the fixed line. None of its parts move during thecutting of a lateral and it serves as a housing for the running line.The running line is of fragile design in that low safety factors andmaterials chosen for lightness and strength are used. Thus in aninstallation suitable for drilling a 100 foot lateral of 1 4 inch borefrom the bottom of a 1000 foot well, the fixed line will weigh in excessof 1 tons whereas the entire running line including drill, fluid motor,high pressure hose, hydraulic pistons and connecting cable weighs wellunder 200 pounds.

. This lightness of the running line is obtained through an arrangementof hydraulic cylinders, one of which is carried at the top of the fixedline and one at its bottom, by which feeding pressure is converted to atensile load sustained by a light cable connecting the pistons of thetwo cylinders. This arrangement also makes possible a successivereduction in crosssection of the fixed line from the surface to the hoseturner at the bottom of the well bore, thereby permitting easy runningor withdrawal of the entire running line from the hole. Through suchcompactness and lightness of the running line, and the conversion offeeding pressures to tensile loads, the sensitivity of the surfacehydraulic cylinder is increased to a point where theoperator can readilysynchronize the cylinder control valves to maintain the desiredfrequency meter reading.

. With these considerations in mind the objects of this invention may bestated as being:

1. Provision of a method for surface control of the feeding pressure ofa lateral drill operated by a fluid motor in which variations in thefrequency of the drill in response to variations in feeding pressure areindicated at the surface through the medium of shock waves carried bythe fluid supply line and are. utilized there as a guide inhydraulically varying the force acting to extend the drill horizontallyfrom the well bore. I

2. Provision of apparatus for feeding a high pressure hose into a hoseturning case for transverse projection therefrom in which the pistons ofhydraulic cylinders of different cross-section integral with either endof a tubing string are connected by a cable as a result of which fluidentering the tubing under pressure between the cylinders acts to movethe cable in the direction of the larger cylinder until manuallycontrolled means for equalizing the pressure on the larger piston causethe cable to move in the opposite direction by reason of the fluidpressure exerted against the smaller piston.

3. The provision of apparatus of the nature described, suitable forrunning in a well bore and in which the valves for equalizing the fluidpressure effective against the larger piston are at the surface whereasthe side opening of the hose turner case carried below the smallercylinder lies opposite a fluid bearing formation.

4. The provision of apparatus of the nature described, in which a highpressure hose carried below the smaller piston communicates with theinside of the tubing so that a high pressure fluid stream is conductedto the hydraulically operated drill carried on its extending end.

5. The provision of apparatus of the nature described, in which themanually controlled fluid pressure maintained above the larger pistondirectly reflects the feeding pressure maintained on the hydraulic drillcarried on the extending end of the hose being projected transverselyfrom a well bore, and indicating means at the surface responsive tovariations in the frequency of the drill to serve as a guide incorrecting discrepancies between the pressure above the piston and thatactually being maintained against the formation face being drilled.

6. The provision of apparatus of the nature described, in whichbeginning at the surface the cross-section of the elements comprisingthe fixed string decreases successively to the lower hydraulic cylinderto permit free running and withdrawal of the running line from theinside of the fixed line.

7. The provision of apparatus of the nature described, in which ameasuring line carried in a well parallel to the fixed line andcommunicating directly with the upper hydraulic cylinder at the fixedstring head, passes over a pulley to be afiixed to the top of the largerpiston in order that the operator upon looking through a window in thetop of the tubing head may know at all times the distance of the drillcarried at the end of the running string has been projected from themain well bore.

Ancillary objectives such as the proper arrangement of valves, pressureguages, air bleeders, caps, cable swivels and the like, will becomeclearer from reading the following description taken in conjunction withthe accompanying drawings in which:

Figure 1 is a diagrammatic sketch showing the arrangement of the fixedstring of elements in hose feeding apparatus, such as that embodied inthis invention, disposed in a well bore, and in which a hydraulicallyoperated drill carried on a high pressure hose is projected horizontallytherefrom.

Fig. 2 is an enlarged cross-sectional view of the apparatus shown inFigure 1 in which parts have been fore-shortened and the essentialelements have been enlarged in order to more clearly illustrate theiroperation, and

Fig. 8 is an enlarged sectional view of the hollow piston and hoseconnection taken from the lower cylinder of Figure 2.

Referring to Fig. '1 an anchor 8 seated at the SIzARCH @0593 bottom of awell bore 5 carries a hose turner case 4 containing a hose conductingpassageway 6 opening against a fluid bearing formation 1 in whichlaterals 9 are to be cut by a fluid operated drill 22 carried on highpressure hose 20 which passes back through passageway 6 and into thehydraulic cylinder I2 carried above the turner case 4 by collar I0. Thecylinder I2 is slightly longer than the hose 20 or the length of thelateral 9 which is to be drilled, and at its upper end is secured to aswedge coupling I4 to carry the tubing string I6 which is slightlylarger in crosssection than the cross-section of the cylinder I2 theinside diameter of which is slightly greater than the diameter of thehead of the drill 22 carried by hose 20 to permit passage of the lattertherethrough.

The tubing string I6 continues upward in the wellbore 5 to a point belowthe surface slightly less than the length of the hydraulic cylinder I2at which point it carries a swedged coupling I8 having side outlet I9for the fluid supply line 30 which continues up to the surface besidethe larger hydraulic cylinder 24 screwed in the top of coupling I8. Theupper end of cylinder 24 carries a head 26, normally covered by aninstrument protecting case 28 when the apparatus is not in operation.

The head 26, Fig. 2, of the fixed string is a casting usually positionedabout two feet above the derrick floor of a conventional drilling rigused for running the apparatus into the hole 5. This casting 26 forms afluid chamber having a top plug 82 larger than the cross-section ofcylinder 24 and aligned therewith. A side chamber 13 in the head 26 hasa hole 16 in its bottom into which is run tubing well 10 through alignedand canted plug hole I9. Well 10 which is of inch tubing and slightlylonger than cylinder 24 carries cap II at its bottom and is solidlysecured and sealed in head 26 at its upper end by collar 15 which restson a resilient washer. Well 10 carries a steel measuring tape I13 havinga weight 14 on its lower end and at its upper end passes over pulley 11to be fixed to clamp 69 of the upper cylinder piston 60. In passing overpulley 11 the figures of tape I13 are maintained on the outside so thatthey are visible to the operator when looking through window in plug 18which seals head opening 19.

At the opposite side of .head 26, the fluid line 8'! screws in hole 88and carries needle valve 90 opening fluid escape line 34 and needlevalve 92 communicating with fluid supply line 30 through tee 93 and line32, an upward extension of which carries platform 95 on which vibratingreed frequency meter I00 is secured as well as fluid supply line guage94. Fluid guage 84 which indicates the feeding pressure in the lateralbeing cut is mounted in the top of plug 82. Beneath plug 82 and insideof head 26 a stop bar 86 rests on top of cylinder 24 to arrest upwardtravel of piston 60 and thus prevent damage to measuring line I2 whileat the same time positioning piston 60 so it may be caught by clampscrew I02 operative in cylinder Wall hole I03. Valve I beneath it is anair bleeder valve for the cylinder 24.

A high pressure hose 38 running from a high pressure fluid pump connectsto the fluid supply line 30 carrying valve 36 at the derrick floor. Thisfluid supply line, the head 26 and parts secured thereto including thewell 10, cylinders I2 and 24, tubing I6, hose turner 4 and anchor 8constitute the fixed line of the apparatus.

The running line is composed of the water drill 22 mounted on highpressure hose 20 which is secured to hollow fitting 58, Fig. 3, havingthreaded end 5'! carried at the lower end of hollow piston body 40threaded at its upper end to receive hollow cup spindle 48 whichadjustably secures spacer 45 and hydraulic cups 42 and 43, to the top ofpiston 40. The hollow head of spindle 48 has holes 54 in its sidewallsto permit a free flow of fluid through piston 40 and into hose 20. andthe top 49 of the head is tapered to receive and secure the babbittedlower end 52 of line cable 50. Cable 50 passes up through tubing I6where it is secured to swivel 66 carried at the bottom of the solidpiston barrel 64 operative in upper cylinder 24. Piston 60 is ofordinary construction, having downward facing cups SI and spacer 62secured by piston head 68.

In operation, after running of the fixed string, valve 36 is openeduntil the well bore 5 fills with water. Plug 82 is removed from the head26 and the running line fed inside the fixed line until piston 60 iscaught by clamp I02. The lowering cable, not shown, is then removed fromclamp 69 and the end of measuring tape I13 secured to the clamp in itsstead. Stop 86 is inserted in the head and plug 82 replaced. Beforetightening plug 82, drain valve 90 is closed and needle valve 92 openedand line valve 36 cracked to fill well 10 and the chamber of head 26with fluid. Cylinder valve I05 is also opened to let any air trappedunder piston 60 escape. When all air has been exhausted from inside theapparatus, plug 82 is tightened and valve I05 closed.

Needle valve 92 is then closed and line valve 36 opened; Guage 94 thenindicates the line pressure and guage 84 a lesser pressure effectiveabove the piston 60. The piston clamp I02 is now released and the piston60 is forced up in cylinder 24 until head .guage 84 registers a headpressure which represents the cross-sectional area of cylinder 24 timesthe line pressure less the weight of the running line and a force equalto the cross-sectional area of the lower and small cylinder 12 times theline pressure. The ratio of the diameter of cylinder 24 to the diameterof cylinder I2 is considered satisfactory when the pressure shown onguage 84 times the cross-sectional area of piston 60, is substantiallyequal to the downward acting force effective upon piston 40.

Idling operation of drill 22 has already begun and frequency meter I00is plugged in to record it. The operator standing in a position toobserve the guages and the tape I13 seen through window cracks needlevalve 92 thereby increasing the reading of guage 84 and directlreflecting the feeding pressure effective upon the drill 22 as 0 "hose20 is pushed down cylinder I2 by piston 40. 6

The distance traveled can be observed on tape I13 and the ratecontrolled accordingly by variation of valve 92. As the drill passesthrough hose turner 4 its fluid engine, the operation of which isdescribed in detail in co-pending application Serial No. 687,028, nowabandoned, kills but takes off again as soon as the drill enters thehorizontal positioning space in the hose turner 4. With continued travelthe drill 22 contacts the formation face and begins to cut drainagelateral 9.

With cutting the frequency of the drill engine increases, and the shockwaves propagated by its action record on the frequency meter. If thefrequency increases too rapidly, the operator decreases the opening ofvalve 92, or if the frequency remains too low opens the valve slightly.

In the event the engine is fed too fast and kills, the operator closesfeed valve 92 and opens drain valve 90, thus retracting the drill untilthe engine takes off again after which he begins feeding it again at a,slower rate. Feeding continues in this manner until tape I13 shows thatthe lateral has been completed?""valve f'is then closed, and drain valve90 opened. The running line then reverses its direction until piston 60contacts stop 86 at which time the screw I03 is used to lock piston 60and line valve 36 is closed, head plug82 is removed, tape H3 isunclamped, and the running. line pulled from the hole. The drill engine22 is removed and replaced with a new drill. The fixed string is raisedofl bottom, turned through the desired angle to position the turner caseagainst a new formation face, and then reset. The process described isthen repeated in drilling a new lateral.

I claim:

1. In well drilling apparatus, the combination of a rigid conduitpositioned in a well bore and having a hydrauliceylinder integral withthe upper end thereof, and a second hydraulic cylinder of differentdiameter integral with the lower end thereof, means for supplying fluidto said conduit intermediate said cylinders, a piston operative in eachof said cylinders, connecting means. for the pistons of said cylinders,drilling means mounted below the lower of said pistons for traveltherewith, pressure varying means mounted at the surface and above theupper piston, whereby fluid introduced under pressure into the conduitbetween said cylinders acts to extend or retract said drilling means inresponse to pressure variation above the upper piston.

2. In well drilling apparatus, hydraulic means for varying the feedingpressure of a drill, positioned in a well bore and operated by a fluidmotor integral therewith, including a fluid conduit communicating withsaid motor, interconnected hydraulic cylinders integral with saidconduit interconnected pistons operative in said cylinders, surfacemeans controlling the extension and retraction of said drill by saidcylinders, and surface means indicating the feeding pressure of saiddrill against the formation being drilled.

3. In surface apparatus controlling the feed- .ing rate of a mechanismfor cutting lateral drainage channels from a well bore, the combinationof a frequency meter indicating the frequency of said mechanism, a,cylinder varying a piston hydraulically extending said mechanism fromsaid well bore, an associated surface controlled cylinder carrying apiston hydraulically retracting said mechanism from said well bore, aline for measuring the distance said mechanism has been projected, andpressure guages recording the fluid force available to produce lateraltravel of said mechanism.

4. In surface apparatus controlling the feeding rate of a mechanism forcutting lateral drainage channels from a well bore, a head carried by afluid conduit positioned in said well, a hydraulic cylinder below saidhead, a piston in said cylinder operative to extend or retract saidmechanism from said well bore in response to operation of paired fluidvalves mounted on said head, a fluid sealed measuring device fixed tosaid piston and passing through said head, a window in said head forobserving said measuring device, a pressure guage in said headindicating the pressure available to extend or retract said mechanism,and a frequency meter mounted on said head for indicating the pressureexerted by said mechanism against the formation face.

5. In apparatus for drilling horizontal drainage channels from a wellbore, a conduit turning case positioned opposite a fluid bearingformation, a hydraulic cylinder positioned above said case andcommunicating therewith, a hollow piston operative in said cylinder, aflexible conduit fixed below said piston and communicating with a fluidconduit extending from said cylinder to the surface, a fluid drill fixedto the extending end of said flexible conduit and responsive to fluidpressure above said piston for lateral extension from said case, and ahydraulically controlled cable extending from the top of said piston tothe surface whereby the fluid force effective against said piston andsaid fluid drill to eject them from said cylinder is variably opposed bya tensile force acting to retract them from said cylinder.

6. In apparatus of the class described in claim 1, the combination withsurface means indicating the frequency of the drill, whereby the optimumrate of extension of" said drill is indicated.

' RUSSELL R. HAYS.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date Re. 21,102 Jakosky May 30, 1939469,187 Tremain Feb. 16, 1892 1,082,901 Perkins Dec. 30, 1913 1,660,201Lee Feb. 21, 1928 1,895,901 Smith Jan. 31, 1933 1,896,110 Simmons Feb.7, 1933 1,954,176 Johnson Apr. 10, 1934 2,192,909 Hoffar Mar. 12, 19402,276,016 Brantly Mar. 10, 1942 2,345,816 Hays Apr. 4, 1944 2,347,302Twyman et a1 Apr. 25, 1944 2,441,881 Hays May 18, 1948

